The present invention generally relates to reclosable polymeric bags and, more particularly, to a reclosable polymeric bag having end terminations.
A reclosable polymeric bag typically includes first and second opposing panels fixedly connected to each other along a pair of sides and a bottom bridging the pair of sides. The first and second panels are not fixedly connected along a mouth which is formed opposite to the sealed or folded bottom. Rather, the bag is provided with a reclosable zipper extending along the mouth of the polymeric bag. The zipper includes a male track and a female track. In reclosable polymeric bags of the type disclosed in U.S. Pat. No. 5,067,208 utilizing a slider to open the zipper, the male track typically includes a male profile and a first fin extending downward from the male profile. Likewise, the female track in such bags with sliders includes a female profile and a second fin extending downward from the female profile. The first and second fins are thermally fused to the inner surfaces of the respective first and second panels.
The male and female profiles are releasably engageable to each other. When the slider is in a closed position, the male and female profiles are interlocked with each other. In response to moving the slider to an open position, the male and female profiles are disengaged from each other. Once the male and female profiles are disengaged from each other, access to the interior of the bag may be obtained by pulling the first and second panels apart at the mouth.
Opposite ends of the zipper are typically provided with end terminations. The end terminations may perform numerous functions, such as (a) preventing or inhibiting the slider from going past the ends of the fastener, (b) interacting with the slider to give a tactile indication of being closed, (c) assisting in inhibiting or preventing leakage from the bag, and (d) holding the fastener together and providing additional strength in resisting stresses to the bag.
In some applications, each end termination is in the form of a strap/clip that wraps over the top of the zipper One end of the strap is provided with a rivet-like member that penetrates through the zipper fins and into a cooperating opening at the other end of the strap.
One of the major drawbacks of these and other existing end terminations is the production time, as compared to production times of other steps in the manufacturing process. Since the end terminations are only one step in forming the polymeric bags, it is important that the production time of the end terminations be in concert with the other steps. Another drawback experienced by some end terminations is found when the end termination is removed from the mold. In some end terminations, xe2x80x9cstringers,xe2x80x9d or threads of the mixture, do not completely break free from the mold and cause problems in the production process. Another drawback of present end terminations is that the strap is a separate part that must be attached to the zipper. This creates another step in the manufacturing process. Also, since the strap has to be manufactured separately, it is often more expensive than is desirable.
The present invention is a process for preparing an end termination for use with a reclosable polymeric bag. First, a mixture is provided that comprises from about 70 to about 95 wt. % of a polyolefin, from about 5 to about 25 wt. % hydrocarbon, from about 0.01 to about 2 wt. % mold release agent, from about 0.01 to about 0.3 wt. % primary antioxidant, and at least about 0.03 wt. % secondary antioxidant. Next, the mixture is heated approximately to its appropriate application temperature and the melted mixture is injected into a mold. After the mixture is cooled to form the end termination, the end termination is ejected from the mold.
The above summary of the present invention is not intended to represent each embodiment or every aspect of the present invention. This is the purpose of the Figures and the detailed description which follow.